title: Immunization with a low dose of hemagglutinin-encoding plasmid protects against 2009 H1N1 pandemic influenza virus in mice.
abstract: A vaccine against the novel pandemic influenza virus (2009 H1N1) is available, but several problems in preparation of vaccines against the new emerging influenza viruses need to be overcome. DNA vaccines represent a novel and powerful alternative to conventional vaccine approaches. To evaluate the ability of a DNA vaccine encoding the hemagglutinin (HA) of 2009 H1N1 to generate humoral responses and protective immunity, BALB/c mice were immunized with various doses of 2009 H1N1 HA-encoding plasmid and anti-HA total IgG, hemagglutination inhibition antibodies and neutralizing antibodies were assayed. The total IgG titers against HA correlated positively with the doses of DNA vaccine, but immunization with either a low dose (10 μg) or a higher dose (25-200 μg) of HA plasmid resulted in similar titers of hemagglutination inhibition and neutralizing antibodies, following a single booster. Further, 10 μg plasmid conferred effective protection against lethal virus challenge. These results suggested that the DNA vaccine encoding the HA of 2009 H1N1 virus is highly effective for inducing neutralizing antibodies and protective immunity. DNA vaccines are a promising new strategy for the rapid development of efficient vaccines to control new emerging pandemic influenza viruses.
authors.affiliation: Department of Microbiology, Shanghai Key Laboratory of Medical Biodefense, Second Military Medical University, 800 Xiangyin Road, Shanghai 200433, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Fang
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Chen
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Liu
authors.forename: Huaifang
authors.initials: H
authors.lastname: Li
authors.forename: Jianjun
authors.initials: J
authors.lastname: Wang
authors.forename: Xiaona
authors.initials: X
authors.lastname: Shen
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liu
authors.forename: Yue
authors.initials: Y
authors.lastname: Wang
authors.forename: Ping
authors.initials: P
authors.lastname: Zhao
authors.forename: Zhongtian
authors.initials: Z
authors.lastname: Qi
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral / Q000097:blood; D005260:Female; D006385:Hemagglutination Inhibition Tests; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics / Q000276:immunology*; D007117:Immunization, Secondary / Q000379:methods; D007074:Immunoglobulin G / Q000097:blood; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D009500:Neutralization Tests; D010957:Plasmids; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007074:Immunoglobulin G; D007252:Influenza Vaccines; D019444:Vaccines, DNA